1. Field of the Invention
The present invention generally relates to capacitor structures and, in particular, to interdigitated capacitor structures incorporating overlays formed of dielectric materials and methods of manufacture.
2. Description of the Related Art
Reducing the size of electronic components oftentimes is problematic as performance characteristics of some of these components are directly related to their physical size. In regard to capacitors, for example, a reduction in the size of a capacitor, i.e., a reduction in the surface area of the plates of the capacitor, typically results in a loss of capacitance.
Heretofore, in applications where use of a capacitor is required and available space for the placement of such a capacitor is limited, interdigitated capacitor structures have been utilized. As is known, an interdigitated capacitor structure includes two contacts, which are spaced from each other, with each contact incorporating one or more protrusions or fingers that are adapted to be interdisposed or interdigitated relative to each other. Such a structure offers a circuit designer a range of flexibility as the capacitance of the structure may be adjusted by altering the spacing between the contacts as well as by changing the number of fingers of the contacts. However, inherent manufacturing considerations of interdigitated capacitors tend to limit the capacitance typically made available by such structures. Such considerations include difficulty in reducing spacing between the fingers of the contacts as the precision limits of an etching process utilized to form the fingers is approached, among others. Thus, heretofore, the limitations imposed upon interdigitated capacitor structures by manufacturing considerations, for example, has enabled such structures to provide only a relatively small improvement in capacitance as compared with other capacitor structures.
Therefore, there is a need for improved interdigitated capacitor structures and methods which address these and other shortcomings of the prior art.
Briefly described, the present invention relates to capacitor structures. In this regard, embodiments of the present invention may be construed as providing methods for forming interdigitated capacitors. In a preferred embodiment, the method includes providing a substrate and depositing a capacitor material upon the substrate. A portion of the capacitor material is then removed, such as by an etching process, to form an interdigitated capacitor structure that incorporates a first contact and a second contact. Thereafter, a dielectric material is applied upon the interdigitated capacitor structure so that the structure is at least partially encapsulated by the dielectric material upon the substrate.
Some embodiments of the present invention may be construed as providing interdigitated capacitor structures. A preferred interdigitated capacitor includes a substrate with first and second contacts formed thereon. Preferably, the first contact incorporates at least a first finger and a second finger, and the second contact incorporates least a first finger, with the fingers engaging each other in an interdigitatedconfiguration. Additionally, a dielectric material is engaged about at least a portion of the first contact, the second contact, and the substrate so that the dielectric material and the substrate encapsulate at least a portion the first and second contacts.
An alternative embodiment of the interdigitated capacitor includes a substrate with first and second contacts formed thereon. Preferably, the first contact incorporates at least a first finger and a second finger, and the second contact incorporates at least a first finger, with the fingers engaging each other in an interdigitated configuration. Additionally, means for increasing capacitance of the interdigitated capacitor is provided.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such features and advantages be included herein within the scope of the present invention, as defined in the appended claims.